In recent years, in the motion picture exhibition field, there has been a growing trend towards automated and semi-automated motion picture theaters. The end objective is to provide a motion picture theater with a totally unattended projection room during normal hours programming and required services of a skilled projectionist only for the steps of loading a projector with a film prior to showing and at the rewinding at the conclusion of the performance. Recent developments in improved light sources for motion picture projectors as disclosed in U.S. Pat. No. 3,720,460 have eliminated the need of continuous monitoring of projection lamps.
A typical evening showing in a commercial theater includes 3 to 4 hours for projection, possibly with one intermission, constituting the handling on one reel for such a full evening performance, has not effectively been accomplished. A full three to four hour reel of 35 mm or wider film constitutes 36-40 inches diameter mass, weighing between 50 and 100 pounds. Not only is it difficult to handle in loading but the requirements in loading are severe, namely the great momentum of such reel of film, the danger of undue stress on the film by the transport system, the need to sense film breakage and make immediate recovery, all have heretofore constituted problems which have not been solved.
Attempts have been made to produce transport systems exploying a number of vertically arranged large flat platters which support the film in two or three segments but such platter mountings have taken a large area of floor space close to the projector and in addition to lack of completely satisfactory performance, have necessarily involved twisting of the film to assume the appropriate plane of travel through the projector.
In line type of large film handling devices have also been developed which provide a mount for a projector, however, such devices have limited film capacity.
An even more significant limitation in the prior art is the fact that in the handling of large reels of film, typically independent drive motors have been used for supply and take-up and any deviation in drive speed of the supplier or take-up can result in film tension producing film breakage.